The mariners magazine, or, Sturmy's mathematical and practical arts containing the description and use of the scale of scales, it being a mathematical ruler, that resolves most mathematical conclusions, and likewise the making and use of the crostaff, quadrant, and the quadrat, nocturnals, and other most useful instruments for all artists and navigators : the art of navigation, resolved geometrically, instrumentally, and by calculation, and by that late excellent invention of logarithms, in the three principal kinds of sailing : with new tables of the longitude and latitude of the most eminent places ... : together with a discourse of the practick part of navigation ..., a new way of surveying land ..., the art of gauging all sorts of vessels ..., the art of dialling by a gnomical scale ... : whereunto is annexed, an abridgment of the penalties and forfeitures, by acts of parliaments appointed, relating to the customs and navigation : also a compendium of fortification, both geometrically and instrumentally / by Capt. Samuel Sturmy.

How to calculate the Height of the Stile, and the Points of Hour-distance from the Meridian.

SUppose the length of the Horizontal Line AB or FE be 12 Inches, and that it were required to put on all the Hours from 7 in the morning to 5 in the even∣ing; here we have 5 hours and 6 inches on either side of the Meridian, ••herefore I allow 15 Degrees for an hour. The Rule to find the height of the Stile is,

As the Tangent-compl. of the given Hour 15 deg.	1057194
Is to half the Horizon or Distance from the Meridian 6 inches	277815
So is the Tangent of 45 Degrees	1000000
To the ••eight of the 〈…〉〈…〉 inches and parts	220621

And likewise the distance of the Hour points of 9 and 3 from the Meridian will be 1 61/100, or 1 inch and 61 parts of 100.